Marinus soars on positive new data for ganaxolone

US biopharma firm Marinus Pharmaceuticals (Nasdaq: MRNS) saw its shares surge as much as 49% after it announced positive preliminary data from the initial CDKL5 patients enrolled in its ongoing Phase II open-label study evaluating its CNS-selective GABAA modulator, ganaxolone, as a treatment for orphan, genetic disorders. The stock was still up more than 20% at $1.40 in after-hours trading.

CDKL5 is a severe, rare genetic disorder that results in early-onset, difficult-to-control seizures, and neuro-developmental impairment. Enrollment is continuing in the study with top-line data expected in mid-2017.

Four patients have been enrolled in this cohort of the study and received up to 1800mg/kg of ganaxolone per day for an average treatment duration of five-months. Three of the four patients experienced a notable reduction in seizure frequency compared to baseline ranging from 52% to 88%. All responders continue to receive treatment, two of whom have completed six-months of treatment and have elected to participate in the study extension.  One patient discontinued the study after four-months of treatment due to lack of efficacy. Safety data to date are consistent with earlier studies where ganaxolone has shown to be generally safe and well-tolerated.